py: Add lsl/lsr/asr opcode support to inline Thumb2 assembler.

tests/inlineasm/asmshift.py

@@ -0,0 +1,29 @@
+@micropython.asm_thumb
+def lsl1(r0):
+    lsl(r0, r0, 1)
+print(hex(lsl1(0x123)))
+
+@micropython.asm_thumb
+def lsl23(r0):
+    lsl(r0, r0, 23)
+print(hex(lsl23(1)))
+
+@micropython.asm_thumb
+def lsr1(r0):
+    lsr(r0, r0, 1)
+print(hex(lsr1(0x123)))
+
+@micropython.asm_thumb
+def lsr31(r0):
+    lsr(r0, r0, 31)
+print(hex(lsr31(0x80000000)))
+
+@micropython.asm_thumb
+def asr1(r0):
+    asr(r0, r0, 1)
+print(hex(asr1(0x123)))
+
+@micropython.asm_thumb
+def asr31(r0):
+    asr(r0, r0, 31)
+print(hex(asr31(0x80000000)))

tests/inlineasm/asmshift.py.exp

@@ -0,0 +1,6 @@
+0x246
+0x800000
+0x91
+0x1
+0x91
+-0x1